This invention relates to the augmentation or supplementation of semiconductor materials by hetero-atoms, and, more particularly to the doping or alloying of semiconductor materials by hetero-atoms.
In order to provide semiconductor materials with prescribed electrical and physical characteristics, it is common practice to add hetero-atoms to the material. For example, silicon can be used in the production of photovoltaic devices for the conversion of sunlight to electrical energy by the introduction of dopants, such as phosphorus or boron atoms to produce a layered photovoltaic cell. A typical photovoltaic cell of amorphous material includes an intrinsic layer of a semiconductor, such as silicon, which is sandwiched between respective doped layers to provide for the respective generation of holes and electrons in the presence of solar excitation. Thus, the generator of holes can be produced by the boron doping of silicon, while the generator of electrons can be produced by the phosphorus doping of silicon.
The most common technique for doping amorphous materials involves the introduction of the dopant in gaseous form into a reaction chamber with basic feed stock, which is generally a semiconductor hydride. While this procedure can produce satisfactory devices, it is necessary to carefully control the rate of deposition and the concentration of the dopant or hetero-atom.
Accordingly, it is an object of the invention to facilitate the production of semiconductor materials having prescribed characteristics.
A related object is to facilitate the production of doped and alloyed semiconductors. Still another related object is to facilitate the production of doped silicon and germanium as well as their alloys.
A further object of the invention is to achieve enhanced control over the rate at which the deposition of doped and alloyed semiconductors takes place.
A still further object of the invention is to achieve increased control over the concentration of the dopant or alloying atoms that are introduced as hetero-atoms into semiconductor materials.